<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.6.10/dist/vue.js"></script>
</head>

<body>
    <div id="app">
        <button @click="fullName='li xiaoxiao'">change</button>
        <h2>全名是{{fullName}}</h2>
    </div>
    <script>
        Vue.config.productionTip = false;

        const vm = new Vue({
            el: "#app",
            data() {
                return {
                    firstName: "Wang",
                    lastName: "zhongwang",
                }
            },

            //computed配置项,内部专门用来书写计算属性
            computed: {

                //以下书写方式就是代表当前计算属性是只读的
                // fullName() {}

                //计算属性可读可写(当获取fullName的值的时候就调用getter函数,当对fullName进行设置的时候,会调用setter函数)
                fullName: {
                    get() {
                        console.log("getter");
                        return (
                            this.firstName.toLowerCase() + " " + this.lastName.toLowerCase()
                        )
                    },
                    set(val) {
                        /* set函数中的参数就是计算属性被设置的值 */

                        console.log("setter", val);

                        //setter中的逻辑我们可以自由发挥
                        this.firstName = val.split(" ")[0];
                        this.lastName = val.split(" ")[1];
                    }
                }
            }
        })
    </script>
</body>

</html>